Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B7/00—Radio transmission systems, i.e. using radiation field
  • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B7/00—Radio transmission systems, i.e. using radiation field
  • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
  • H04B7/022—Site diversity; Macro-diversity
  • H04B7/024—Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04J—MULTIPLEX COMMUNICATION
  • H04J11/00—Orthogonal multiplex systems, e.g. using WALSH codes
  • H04J11/0023—Interference mitigation or co-ordination
  • H04J11/005—Interference mitigation or co-ordination of intercell interference
  • H04J11/0053—Interference mitigation or co-ordination of intercell interference using co-ordinated multipoint transmission/reception
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L25/00—Baseband systems
  • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
  • H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
  • H04L25/03891—Spatial equalizers
  • H04L25/03898—Spatial equalizers codebook-based design
  • H04L25/03904—Spatial equalizers codebook-based design cooperative design, e.g. exchanging of codebook information between base stations
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
  • H04W88/02—Terminal devices
  • H04W88/04—Terminal devices adapted for relaying to or from another terminal or user
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
  • H04W88/08—Access point devices
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L5/00—Arrangements affording multiple use of the transmission path
  • H04L5/0001—Arrangements for dividing the transmission path
  • H04L5/0003—Two-dimensional division
  • H04L5/0005—Time-frequency
  • H04L5/0007—Time-frequency the frequencies being orthogonal, e.g. OFDM(A), DMT
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L5/00—Arrangements affording multiple use of the transmission path
  • H04L5/003—Arrangements for allocating sub-channels of the transmission path
  • H04L5/0032—Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
  • H04L5/0035—Resource allocation in a cooperative multipoint environment
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W72/00—Local resource management
  • H04W72/50—Allocation or scheduling criteria for wireless resources
  • H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria
  • H04W72/542—Allocation or scheduling criteria for wireless resources based on quality criteria using measured or perceived quality

Definitions

• the present invention relates to wireless communication technologies, and more particularly to a method and apparatus for multi-base station or multi-cell cooperative communication in a wireless communication system. Background technique
• the space-time processing technology of multi-antenna systems mainly includes spatial multiplexing and spatial diversity.
• Spatial diversity is that space-time coding divides data into multiple data substreams simultaneously on multiple antennas, and diversity gain is obtained by introducing coding redundancy in the time domain between transmit antennas.
• Spatial multiplexing is to send an independent stream of information at the transmitting antenna, and the receiving end uses the method of interference suppression to achieve maximum rate.
• space multiplexing techniques can be used to increase the throughput of wireless communication systems, while spatial diversity techniques can be used to extend the coverage of wireless communication systems.
• the user at the cell edge is far away from the serving base station, the signal received by the serving base station is weak, and the interference from the neighboring cell base station signal is also large, thereby deteriorating the system throughput of the cell edge user.
• Patent Document 1 COX TIMOTHY [US] ; KHOSHNEVIS AHMAD [US] , COOPERATIVE MULTIPLE ACCESS IN WIRELESS NETWORKS (W02008157147);
• Patent Document 2 SHEN MANYUAN [US] ; XING GUANBIN [US] , Cooperative
• Patent Document 3 LI ANXIN [CN] ; LI XIANGMING [CN], UPLINK MULTIPLE-INPUT-MULTIPLE-OUTPUT (MIMO) AND COOPERATIVE MIMO TRANSMISSIONS (W02008124535);
• Patent Document 4 MEHTA NEELESH B [US]; ZHANG HONGYUAN [US], System and method for transmitting signals in cooperative base station multi-user MIMO networks (US2007248172);
• Patent Document 5 KIM SUNG JIN [KR] ; KIM HO JIN [KR], METHOD FOR COOPERATIVE DIVERSITY IN MIMO WIRELESS NETWORK (KR20060111238);
• Patent Document 6 KIM SUNG-JIN [KR] ; KIM HO-JI [KR], Method of providing cooperative diversity in a MIMO wireless network (US2006239222);
• Non-Patent Document 1 Ayman F. Naguid, Vahid Tarokh, Nambirajan Seshadri, A. Robert Calderbank, "A Space-Time Coding Modem for High-Data-Rate Wireless Communications,,, IN IEEE JSAC, vol. 16 , no. 8, October 1998, pp. 1459-1478;
• Non-Patent Document 2 V. Tarokh, N. Seshadri, AR Calderbank, "Space-time codes for high data rate wireless communication: performance criterion and code construction", IEEE Trans. Inform. Theory, 44 : 744- 765, March 1998. Summary of the invention
• Embodiments of the present invention have been made in view of the above problems of the prior art, and are directed to solving one or more of the disadvantages of the prior art, and at least provide a beneficial alternative.
• a communication device comprising:
• a channel estimation unit configured to obtain a cell base station of the communication device and a cell where the communication device is located a channel estimation value between the channel, that is, a channel estimation value between the communication device and the cell base station; and a sending unit, configured to transmit the channel estimation value or information based on the channel estimation value to the cell base station;
• a receiving unit configured to receive a multi-point cooperation message from the cell base station, where the multi-point cooperation message indicates a multi-point cooperative transmission mode, a codebook or a precoding matrix used by the cell base station, and performing with the cell base station a codebook or precoding matrix used by the cooperative cooperative base station;
• a channel matrix forming unit configured to obtain a channel matrix according to the multipoint cooperation message; and a decoding unit that decodes the received signal according to the channel matrix and the multipoint cooperation message.
• the multipoint cooperation message indicates that the coordinated multi-point transmission mode is an associated coordinated multi-point transmission mode
• the channel matrix forming unit pairs the antenna of the cell base station
• the antenna of the cooperative base station performs channel estimation to form a channel matrix
• the decoding unit decodes the received signal by treating data from the cell base station and data from the cooperative base station as the same data.
• the communication device wherein the multipoint cooperation message indicates that the multipoint cooperative transmission mode is a first type of non-correlated multipoint cooperative transmission mode, and the channel matrix forming unit pairs the cell An antenna of the base station and an antenna of the cooperative base station perform channel estimation to form a channel matrix, and the decoding unit decodes the received signal by treating data from the base station and data from the cooperative base station as different data. .
• the communication device wherein the multipoint cooperation message indicates that the multipoint cooperative transmission mode is a second type of non-correlated multipoint cooperative transmission mode, and the channel matrix forming unit pairs the cell
• the antenna of the base station performs channel estimation to form a channel matrix, and the decoding unit decodes the received signal for data from the cell base station.
• the communication device wherein the channel estimation unit further obtains a channel estimation value between the communication device and the cooperative base station; and the transmitting unit connects the communication device to the cooperative base station The channel estimate between the two is transmitted to the cell base station.
• Aspect 6 The communication device according to aspect 1, wherein the channel estimation unit further obtains a channel estimation value of a channel between the communication device and the cooperative base station, that is, a channel estimation between the communication device and the cooperative base station
• the communication device further includes a determining unit, the determining unit determining whether multipoint cooperative transmission should be performed; and when determining that multipoint cooperative transmission should be performed, the sending unit sends a request to the cell base station for multi-point cooperation.
• the transmitted request is used as information based on the channel estimate.
• the communication device wherein the determining unit further determines a multipoint cooperative transmission mode to be adopted and a codebook or precoding matrix to be adopted by the cell base station and the cooperative base station, and the transmitting unit
• the request sent to the cell base station includes information indicating the coordinated cooperative transmission mode and the codebook or precoding matrix.
• the communication device determines to use the second type of non-correlated multi-point cooperative transmission mode according to the a posteriori signal to noise ratio or throughput of the communication device.
• the criteria determine a codebook or precoding matrix that the cell base station should employ, and determine a codebook or precoding matrix that the cooperative base station should employ based on criteria that minimize the a posteriori signal to noise ratio or throughput of the communication device.
• a channel estimation value between the communication device and the cell base station is between a first threshold and a second threshold, and the communication device and the cooperative base station
• the judging unit judges that multi-point cooperative transmission should be performed when the channel estimation value is between the third threshold and the fourth threshold; the channel estimation value between the communication device and the cell base station is lower than the first
• the determining unit determines that the relevant coordinated multi-point transmission mode should be adopted; the channel estimation value between the communication device and the cell base station is higher than the fifth threshold
• the determining unit determines that the first type of related multi-point cooperative transmission mode should be adopted when the channel estimation value between the communication device and the cooperative base station is higher than a sixth threshold between the third threshold and the fourth threshold.
• the determining unit determines that the second type of related multi-point cooperative transmission mode should be adopted.
• a receiving unit receiving, from a communication device in a cell served by the base station, a channel estimation value for a channel between the communication device and the base station, that is, a channel estimation value between the base station and the base station;
• the determining unit determines, according to the channel estimation value, whether multi-point cooperative transmission, a multi-point cooperative transmission mode to be adopted, a codebook or a precoding matrix to be adopted by the base station, and a cooperative base station that cooperates with the base station Information about the codebook or precoding matrix that should be used;
• the first sending unit notifying the cooperative base station of the cooperation information, where the cooperation information includes information indicating the multi-point cooperative transmission mode, a codebook that the cooperative base station should adopt, and the cooperative base station Data that should be sent;
• the second sending unit Transmitting, by the second sending unit, the multi-point cooperative transmission mode indicating that the adopted, the codebook or precoding matrix that the base station should adopt, and the code that the cooperative base station should cooperate with the base station Information of the present or precoding matrix, and data to be received by the communication device.
• Aspect 11 The base station according to aspect 10, wherein the determining unit performs the determining according to the channel estimation value and a geographic location of the communication device.
• Aspect 12 The base station of clause 10, wherein the receiving unit further receives a channel estimate from the communication device for a channel between the communication device and the cooperating base station, ie, with a cooperating base station a channel estimation value; the determining unit performs the determining according to a channel estimation value between the communication device and the cooperative base station and a channel estimation value between the communication device and the base station.
• the base station wherein a channel estimation value between the communication device and the base station is between a first threshold and a second threshold and between the communication device and the cooperative base station
• the determining unit determines that multi-point cooperative transmission should be performed when the channel estimation value is between the third threshold and the fourth threshold; the channel estimation value between the communication device and the base station is lower than the first threshold and the second When the fifth threshold between the thresholds, the determining unit determines that the relevant multipoint cooperative transmission mode should be adopted; the channel estimation value between the communication device and the base station is higher than the fifth threshold, and the communication When the channel estimation value between the device and the cooperative base station is higher than a sixth threshold between the third threshold and the fourth threshold, the determining unit determines that the first type of related coordinated multi-point transmission mode should be adopted; And when a channel estimation value between the device and the base station is higher than the fifth threshold, and a channel estimation value between the communication device and the cooperative base station is lower than the sixth threshold, Determination means determines second type shall be related cooperative multipoint transmission mode.
• Aspect 14 The communication device according to aspect 10, wherein the determining unit determines a posterior signal to noise ratio or throughput of the communication device when determining that a second type of non-correlated multipoint cooperative transmission mode should be employed
• the maximum criterion determines a codebook or precoding matrix that the base station should employ, and determines a codebook or precoding matrix that the cooperative base station should use based on criteria that minimize the a posteriori signal to noise ratio or throughput of the communication device. .
• the communication device wherein, when the determining unit determines that the relevant coordinated multi-point transmission mode should be adopted, the first transmitting unit sends the base station to the cooperative base station to send to the base station
• the data of the communication device is the same data; when the determining unit determines that the first type of related coordinated multi-point transmission mode should be adopted, the first sending unit sends the base station to the cooperative base station to send to the cooperative base station
• the data of the communication device is different data; when the determining unit determines that the first type of related coordinated multi-point transmission mode should be adopted, the first sending unit does not send data to the cooperative base station.
• Aspect 16 a multipoint cooperative communication method used by a communication device, and the multipoint cooperative communication method Including the following steps:
• Receiving receiving a multipoint cooperation message from the cell base station, where the multipoint cooperation message indicates a multipoint cooperative transmission mode, a codebook or precoding matrix used by the cell base station, and cooperation with the cell base station a codebook or precoding matrix used by the cooperative base station;
• a channel matrix forming step obtaining a channel matrix according to the multipoint cooperation message
• the decoding step decodes the received signal according to the channel matrix and the multipoint cooperation message.
• the multi-point cooperative communication method wherein the multi-point cooperation message indicates that the multi-point cooperative transmission mode is a related multi-point cooperative transmission mode, and the channel matrix forming step is performed on the cell.
• the antenna of the base station and the antenna of the cooperative base station perform channel estimation to form a channel matrix, and the decoding step treats the received signal by considering data from the cell base station and data from the cooperative base station as the same data. decoding.
• the multi-point cooperative communication method wherein the multi-point cooperation message indicates that the multi-point cooperative transmission mode is a first type of non-correlated multi-point cooperative transmission mode, and the channel matrix forming step Performing channel estimation on an antenna of the cell base station and an antenna of the cooperative base station to form a channel matrix, where the decoding step treats data from the cell base station and data from the cooperative base station as different data.
• the received signal is decoded.
• the multi-point cooperative communication method wherein the multi-point cooperation message indicates that the multi-point cooperative transmission mode is a second type of non-correlated multi-point cooperative transmission mode, and the channel matrix forming step Channel estimation is performed on the antenna of the cell base station to form a channel matrix, and the decoding step decodes the received signal for data from the cell base station.
• the multi-point cooperative communication method wherein the channel estimation step further obtains a channel estimation value between the communication device and the cooperative base station; The channel estimation value between the cooperative base stations is transmitted to the cell base station.
• the multi-point cooperative communication method further obtains a channel estimation value of a channel between the communication device and the cooperative base station, that is, the communication device and the cooperative base station Channel estimation value between the two; the multipoint cooperative communication method further includes a determining step, The determining unit determines whether multi-point cooperative transmission should be performed; when it is determined that multi-point cooperative transmission should be performed, the transmitting step sends a request for multi-point cooperative transmission to the cell base station, as the channel estimation value is used. information.
• the multi-point cooperative communication method wherein the determining step further determines a multi-point cooperative transmission mode to be adopted and a codebook or a precoding matrix to be adopted by the cell base station and the cooperative base station,
• the request sent by the sending process to the cell base station includes information indicating the coordinated cooperative transmission mode and the codebook or precoding matrix.
• a base station, the base station includes:
• a request for a multi-point cooperative transmission from a communication device in a cell served by the base station includes a multi-point cooperative transmission mode indicating that the base station should adopt a codebook or precoding a matrix, and information of a codebook or a precoding matrix to be used by a cooperative base station in cooperation with the base station;
• the first sending unit notifies the cooperative base station of the cooperation information, where the cooperation information includes information indicating the multi-point cooperative transmission mode, a codebook or a precoding matrix that the cooperative base station should adopt, and The data that the cooperative base station should transmit;
• the second transmitting unit transmits an acknowledgment for the request and data to be received by the communication device to the communication device.
• Aspect 24 The base station according to aspect 23, wherein the base station further comprises a determining unit, the determining unit determining whether the request should be accepted.
• FIG. 1 illustrates a related multipoint cooperative transmission mode in accordance with an embodiment of the present invention.
• FIG. 2 illustrates a first type of non-correlated multi-point cooperative transmission mode in accordance with an embodiment of the present invention.
• FIG. 3 illustrates a second type of non-correlated multi-point cooperative transmission mode in accordance with an embodiment of the present invention.
• FIG. 4 is a flow chart showing an exemplary embodiment of a primary base station selecting a transmission mode.
• FIG. 5 is a flow chart showing another exemplary embodiment in which a primary base station selects a transmission mode.
• Figure 6A illustrates a mobile station in accordance with an embodiment of the present invention.
• Figure 6B illustrates a mobile station in accordance with another embodiment of the present invention.
• Figure 7 shows a schematic functional block diagram of a primary base station in accordance with an embodiment of the present invention.
• Figure 8 shows a schematic functional block diagram of a cooperative base station in accordance with an embodiment of the present invention.
• Figure 9 is a flow chart showing the processing of an embodiment of a communication system consisting of a mobile station, a primary base station, and a cooperative base station.
• Figure 10 is a flow chart showing the processing of another embodiment of a communication system consisting of a mobile station, a primary base station, and a cooperative base station.
• Figure 11 is a flow chart showing a further embodiment of a communication system consisting of a mobile station, a primary base station, and a cooperative base station. detailed description
• the primary base station and the cooperative base station may perform multi-point cooperation on the mobile station by using a related multi-point cooperative transmission mode, a first type of non-correlated multi-point cooperative transmission mode, and a second type of non-correlated multi-point cooperative transmission mode.
• the three multi-point cooperative transmission modes are introduced below.
• FIG. 1 illustrates a related multipoint cooperative transmission mode in accordance with an embodiment of the present invention.
• the primary base station and the cooperative base station jointly serve a mobile station, and the same data is precoded using the same or different codebooks, and the data ⁇ is precoded, passes through the primary base station, and The cooperative base station transmits to the mobile station.
• the mobile station must be on the channel. ( ⁇ and ⁇ ) simultaneously perform channel estimation.
• the master base station may select a codebook for the primary base station itself and the cooperative base station based on the result of the channel estimation, respectively represented as a sum.
• the mobile station may select the codebook ⁇ and the primary base station itself and the cooperative base station based on the result of the channel estimation, and may also be based on the result of the channel estimation by the primary base station.
• the codebook is based on the codebook by the cooperative base station. Choose a codebook.
• the received signal of the mobile station is only interfered by AWGN noise.
• FIG. 2 illustrates a first type of non-correlated multi-point cooperative transmission mode in accordance with an embodiment of the present invention.
• the primary base station and the cooperative base station jointly serve a mobile station, using the same or different codebooks and transmitting different data.
• the mobile station must simultaneously perform channel estimation on the channels rk , 0 and k , l .
• a codebook is selected for the primary base station itself and the cooperative base station, respectively represented as ⁇ and .
• the mobile station may select the codebook ⁇ 7 for the primary base station itself and the cooperative base station based on the result of the channel estimation.
• the primary base station may base itself on a codebook based on the result of the channel estimation, and the cooperative base station according to the codebook. Choose a codebook.
• the transmission data of the primary base station is transmitted to the mobile station after precoding by ⁇ , and the transmission data of the cooperative base station is transmitted to the mobile station after precoding.
• the received signal of the mobile station may also have mutual interference values of the two signals due to the incomplete ideal of the codebook; in addition, it is also interfered by AWGN noise. .
• FIG. 3 illustrates a second type of non-correlated multi-point cooperative transmission mode in accordance with an embodiment of the present invention.
• the primary base station and the cooperative base station serve respective mobile stations, using different or identical codebooks and transmitting different data.
• the mobile station is on channel r . (k , 0 and r , l simultaneously perform channel estimation.
• the master base station may select a codebook based on the result of the channel estimation for the primary base station itself and the cooperative base station, respectively denoted as ⁇ and.
• the cooperative base station selects the codebook according to the codebook.
• the transmission data of the primary base station is sent to the mobile station served by the primary base station after being precoded, and the transmission data of the cooperative base station is sent to the cooperative base station service after being precoded.
• Mobile station The mobile station of the primary base station receives the signal, in addition to receiving the useful signal from the autonomous base station.
• there is interference of the transmitted data signal of the cooperative base station due to the non-complete ideal of the codebook, there is interference of the transmitted data signal of the cooperative base station; in addition, it is also interfered by the AWGN noise.
• the codebook used in the primary base station and the cooperative serving base station respectively is 7 .
• a codebook maximizes the a posteriori signal-to-noise ratio (throughput) of the mobile station
• another codebook minimizes the a posteriori signal-to-noise ratio (throughput) of the mobile station.
• the primary base station transmits a signal serving the mobile station using a base station that maximizes the a posteriori signal to noise ratio (throughput) of the mobile station; and uses a code that minimizes the posterior signal to noise ratio (throughput) of the mobile station.
• the base station transmits a signal serving another mobile station.
• step S401 the primary base station receives between the primary base station and the mobile station from the mobile station, and between the mobile station and the neighboring base station (other base stations adjacent to the primary base station). Channel estimate.
• each mobile station needs to perform channel estimation for the primary base station and each of the neighboring base stations.
• the primary base station can determine whether multi-point cooperation is required according to the current channel condition. For example, in an embodiment, when the channel estimation value between the primary base station and the mobile station is less than the first threshold and greater than the second threshold, and the channel estimation value between the neighboring base station and the mobile station is less than the third threshold and greater than the first When the threshold is four, it is judged that multi-point cooperation is required.
• the channel estimation value between the primary base station and the mobile station is greater than the first threshold, indicating that the channel between the primary base station and the mobile station is very good, and no multi-point cooperation is required.
• the channel estimation value between the primary base station and the mobile station is smaller than the second threshold, indicating that the channel between the primary base station and the mobile station is very bad, and the primary base station is incapable of performing multi-point cooperation. Therefore, in this case, it is determined that there is no need to perform much. Point cooperation.
• the channel estimation value between the neighboring base station and the mobile station is greater than the third threshold, indicating that the channel between the neighboring base station and the mobile station is very good, and no multi-point cooperation is required.
• the channel estimation value between the adjacent and mobile stations is smaller than the fourth threshold, indicating that the channel between the neighboring base station and the mobile station is very bad, and the neighboring base stations are not capable of multi-point cooperation.
• the primary base station further determines which multi-point cooperative transmission mode is required. To this end, in an embodiment of the present invention, in step S403, the primary base station determines whether the channel estimation value between the primary base station and the mobile station is lower than a fifth threshold between the first threshold and the second threshold, If it is lower than the fifth threshold, it is judged that the relevant multi-point cooperative transmission mode needs to be performed. On the other hand, when it is determined in step S403 that the channel estimation value between the primary base station and the mobile station is not lower than the fifth threshold, it is determined in step S404 whether the channel estimation value between the neighboring base station and the mobile station is higher than In the first A sixth threshold between the third threshold and the fourth threshold.
• the sixth threshold it is determined that the first type of non-correlated multi-point cooperative transmission mode needs to be adopted. If it is determined that the value is not higher than the sixth threshold, it is determined that the second type of non-correlated multi-point cooperative transmission mode needs to be adopted.
• FIG. 5 is a flow chart showing another exemplary embodiment in which a primary base station selects a transmission mode.
• the flow shown in FIG. 5 is substantially the same as the flow shown in FIG. 4, but after determining in step S404 that the channel estimation value between the neighboring base station and the mobile station is higher than the sixth threshold, the data is further determined in step S405. Whether the flow is greater than a predetermined value. If it is greater than the predetermined value, the first type of non-correlated multi-point cooperative transmission mode is adopted, otherwise, the second type of uncorrelated multi-point cooperative transmission mode is adopted.
• the mobile station may not measure the channel estimate between the cooperating base station and only the channel estimate between the primary base station and the primary base station.
• the primary base station estimates the channel estimation value between the base station and the cooperative base station based on the geographical location of the mobile station, and further determines whether a coordinated multi-point transmission mode should be adopted and which multi-point cooperative transmission mode should be adopted.
• step S401 may become a step of performing channel estimation.
• Figure 6A illustrates a mobile station in accordance with an embodiment of the present invention.
• the receiver employs ⁇ SE detection, and it is assumed that the receiver is completely identical in time to each base station when receiving the transmission signals of the respective base stations. If the time is different, the time error can be compensated by a simple linear phase adjustment.
• the mobile station 60 includes a channel estimating unit 61, a transmitting unit 62, a receiving unit 63, a channel matrix forming unit 64, and a decoding unit 65.
• the channel estimating unit 61 estimates the channel estimation value with the primary base station and estimates the channel estimation value with the neighboring base station.
• Transmitting unit 62 passes the estimated channel estimate to the primary base station.
• the transmitting unit 62 may also transmit the estimated channel estimate value with the neighboring base station to the neighboring base station.
• the channel estimation unit 61 can estimate only the channel estimation value with the neighboring base station.
• the receiving unit 63 receives information about whether the multi-point cooperative transmission mode is entered when entering the coordinated mode, the multi-point cooperative transmission mode, and the codebook used by the primary base station and the cooperative base station, which are sent by the primary base station. For example, in CDMA, the above information can be sent through the downlink command channel CIPCH channel; In the LTE system, this information can be transmitted through the PDCCH channel. In addition, the receiving unit also receives data from the primary base station and/or neighboring base stations.
• the channel matrix forming unit 64 Upon being notified to enter the related multi-point cooperative transmission mode and the first type of non-correlated multi-point cooperative transmission mode, the channel matrix forming unit 64 forms a channel matrix by performing channel estimation on the antenna of the primary base station and the antenna of the adjacent base station; When entering the second type of non-correlated multi-point cooperative transmission mode, the channel matrix forming unit 64 performs channel estimation on the antenna of the base station serving the user to form a channel matrix.
• the decoding unit 65 decodes data from the primary base station and the adjacent base station based on the channel matrix and the coordinated cooperative transmission mode notified by the primary base station and the channel matrix. Specifically, when it is notified that the related multi-point cooperative transmission mode is entered, the decoding unit 65 regards the data from the different base stations received by the receiving unit 63 on the same resource as the same data, and performs decoding. In the embodiment of the present invention, the same resource refers to the same subcarrier resource of the same symbol at the same time. Upon being notified to enter the first type of related multi-point cooperative transmission mode, the decoding unit 65 regards the data from the different base stations received by the receiving unit 63 on the same resource as different data, and performs decoding. The decoding can be performed using a well-known ⁇ SE receiver, ZF receiver, or the like.
• the primary base station may only inform the mobile station of the incoming multi-point cooperative transmission mode and the second type of non-correlated multi-point cooperative transmission mode.
• Figure 6B illustrates a mobile station in accordance with another embodiment of the present invention.
• the mobile station shown in Fig. 6B adds a judging unit 66 as compared with the mobile station shown in Fig. 6A.
• the judging unit 66 judges whether or not multi-point cooperative transmission is required according to the channel estimation value estimated by the channel estimating unit 61, and which cooperative transmission is performed, and determines a codebook which the main base station and the cooperative base station should use.
• the request for entering the multi-point multi-point cooperative transmission mode including the determined multi-point cooperative transmission mode and the determined codebook is transmitted to the main base station.
• the determining unit 66 may only determine whether multi-point cooperative transmission is required and which cooperative transmission is to be performed without determining the codebook that the primary base station and the cooperative base station should use.
• the receiving unit 63 receives a notification from the primary base station as to whether or not to accept the request of the mobile station.
• the notification further includes the confirmed multipoint cooperative transmission mode, and the codebook to be employed by the primary base station and the cooperative base station.
• Figure 7 shows a schematic functional block diagram of a primary base station in accordance with an embodiment of the present invention.
• the primary base station 70 includes a receiving unit 71, a determining unit 72, and a A transmitting unit 73 and a second transmitting unit 74.
• the receiving unit 71 receives the channel estimate from the mobile station or receives the precoding matrix value from the mobile station.
• the primary base station further includes a channel estimation unit for estimating between the primary base station and the mobile station The channel estimate of the channel.
• the judging unit 72 judges whether to enter the multi-point cooperative transmission mode according to the channel estimation value or the precoding matrix, and enters the multi-point cooperative transmission mode if entering the multi-point cooperative transmission mode.
• the determining unit 72 also determines a coded modulation scheme, a codebook to be used, and the like which the primary base station and the cooperative base station should employ.
• the coded modulation scheme and the codebook used the criterion of the a posteriori SNR or the maximum throughput can be used.
• the a posteriori signal-to-noise ratio maximum criterion used in determining the codebook and the coded modulation scheme that is, in a certain decoding algorithm (such as a zero-forcing algorithm or a ⁇ SE algorithm), selecting a code that maximizes the posterior SNR of the system. And selecting a corresponding code modulation scheme according to the obtained posterior signal to noise ratio;
• the criterion for the highest throughput used in determining the codebook and coded modulation scheme that is, the selection of the system to achieve the throughput of a certain decoding algorithm (such as the zero-forcing algorithm or the ⁇ SE algorithm) and the target frame error rate of the system.
• the largest codebook and coded modulation scheme that is, the selection of the system to achieve the throughput of a certain decoding algorithm (such as the zero-forcing algorithm or the ⁇ SE algorithm) and the target frame error rate of the system.
• the first transmitting unit 73 notifies the cooperative base station of the selected multi-point cooperative transmission mode, for example, through an interface between the base station and the base station (for example, an X2 interface), and selects more relevant
• the point cooperative transmission mode it is used to transmit data to be transmitted to the mobile station by the cooperative base station to the cooperative base station. This data is the same as the data that the primary base station is to send to the mobile station.
• the first type of non-correlated multi-point cooperative transmission mode is selected, the data to be transmitted by the cooperative base station to the mobile station is transmitted to the cooperative base station. This data is different from the data that the primary base station is to send to the mobile station.
• the first transmitting unit 73 also transmits data transmission information indicating a codebook (precoding matrix), a coded modulation scheme, and the like.
• the first transmitting unit 73 can directly transmit information indicating a codebook, a coded modulation scheme, and the like which the cooperative base station should employ.
• the codebook used by the primary base station may also be transmitted, and the cooperative base station determines the codebook that should be used according to the codebook used by the primary base station.
• the first transmission unit 73 collectively transmits cooperation information such as data transmission information and data sent to the cooperative base station.
• the second transmitting unit 74 transmits to the mobile station a multipoint cooperation message indicating which multipoint cooperation mode or the like is employed.
• the second sending unit 74 further sends the coded modulation mode and codebook information used by the primary base station and the coded modulation mode and codebook information used by the cooperative base station to the mobile station.
• the second transmitting unit 74 transmits the primary base to the mobile station. The code modulation mode and codebook information used by the station, but the code modulation mode and codebook information used by the cooperative base station are not transmitted.
• Figure 8 shows a schematic functional block diagram of a cooperative base station in accordance with an embodiment of the present invention.
• the cooperative base station 80 includes a receiving unit 81, a determining unit 82, and a transmitting unit 83.
• the receiving unit 81 receives information indicating whether to enter the multi-point cooperative transmission mode, which multi-point cooperative transmission mode to enter, the coding modulation method to be used, the codebook (precoding matrix), and the like, and the data to be transmitted, etc. from the primary base station. .
• the determining unit 82 determines the code modulation mode and the codebook (precoding matrix) to be used by the cooperative base station based on the information from the primary base station.
• the determining unit directly determines the indicated coded modulation mode and the codebook as the coded modulation mode and codebook to be used (precoding) matrix).
• the primary base station does not perform a direct indication, but only gives a coded modulation scheme and codebook information used by the primary base station, and a channel estimation value between the mobile station and the cooperative base station, the determining unit 82 determines, based on the information, The coded modulation scheme and codebook (precoding matrix) used.
• the transmitting unit 83 Upon being instructed to enter the multipoint cooperative transmission mode, the transmitting unit 83 transmits data to the mobile station based on the coded modulation scheme and the codebook determined by the determining unit 82. Upon entering the relevant coordinated multi-point transmission mode and the first type of non-correlated multi-point cooperative transmission mode, the data transmitted by the transmitting unit 83 is derived from the data transmitted from the primary base station received by the receiving unit. In the second type of non-correlated multi-point cooperative transmission mode, the transmitting unit 83 does not transmit data to the mobile station that needs the multi-point cooperation service, but transmits the data to the mobile station serving itself by using the code modulation scheme, the codebook, etc. notified by the primary base station. To minimize interference to mobile stations that require multiple cooperative services. Since the data of the cooperative base station is also objectively received (as interference) by the mobile station at this time, it is collectively referred to as cooperation data together with the data received from the primary base station.
• the mobile station and each base station contain various other units necessary for realizing their own functions. These other units are, for example, a control unit (such as a CPU) that controls components of the mobile station and the base station, a storage unit that stores data and codebook information, and an interface unit (such as a display and an operation key) that is convenient for a worker or a user to operate. and many more.
• a control unit such as a CPU
• a storage unit that stores data and codebook information
• an interface unit such as a display and an operation key
• Figure 9 is a flow chart showing the processing of an embodiment of a communication system consisting of a mobile station, a primary base station, and a cooperative base station. Although a cooperative base station is shown in the figure, it should be noted that there may be multiple cooperative base stations.
• a mobile station Channel estimation is performed (S91), and channel estimation values of channels between the mobile station and the primary base station and between the mobile station and the cooperative base station are estimated. Then, the mobile station transmits the channel estimation value to the primary base station (S92). The primary base station determines whether to perform multi-point cooperation according to the received channel estimation value, and performs a multi-point cooperative transmission mode (S93) to be used for multi-point cooperation.
• the form of multi-point cooperation is indicated, and the multi-point cooperation message of the coded modulation mode, the codebook, and the like used by the primary base station and the cooperative base station is sent to the mobile station (S94), which will include Cooperative information indicating a multipoint cooperative transmission mode, a coded modulation scheme, a code transmission information of a codebook (precoding matrix), and data (in the case of related cooperation and a first type of non-related cooperation) are transmitted to the cooperative base station (S95) And transmitting data to the mobile station (S96).
• the cooperative base station After receiving the cooperation information from the primary base station, the cooperative base station determines the code modulation mode, the codebook (precoding matrix) used, and the like (S97), and then transmits the cooperation data (S98). Thereafter, the mobile station decodes data from the primary base station and from the cooperative base station according to the multipoint cooperation message sent by the primary base station (S99)
• Figure 10 is a flow chart showing the processing of another embodiment of a communication system consisting of a mobile station, a primary base station, and a cooperative base station.
• channel estimation is first performed by a mobile station (S101), which estimates only a channel estimation value of a channel between a mobile station and a primary base station. Then, the mobile station transmits the channel estimation value to the primary base station (S102). The primary base station determines whether to perform multi-point cooperation according to the received channel estimation value and the geographical position of the mobile station, and performs a multi-point cooperative transmission mode to be used for multi-point cooperation (S103).
• a multi-point cooperation message indicating the form of multi-point cooperation, the coding modulation mode used by the primary base station, the codebook, and the like is transmitted to the mobile station (S104), and the indication includes multiple points.
• the cooperative transmission mode, the coded modulation scheme, the data transmission information of the codebook, and the cooperation information are transmitted to the cooperative base station (S105), and are transmitted to the mobile station.
• the mobile station After receiving the multipoint cooperation information from the primary base station, the mobile station performs channel estimation (S107), and transmits the channel estimation value to the cooperative base station (S108). After receiving the cooperation information from the primary base station and the channel estimation value of the mobile station, the cooperative base station determines a code modulation mode, a used codebook, and the like (S109), and then transmits the determined decoding information to the mobile station (S110), The cooperation data (Slll) is then sent. Thereafter, the mobile station decodes data from the primary base station and from the cooperative base station based on the multipoint cooperation message transmitted by the primary base station and the decoding information transmitted by the cooperative base station (S112).
• FIG. 11 is a flow chart showing the processing of still another embodiment of a communication system consisting of a mobile station, a primary base station, and a cooperative base station.
• channel estimation is first performed by the mobile station (S201), which estimates the channel estimation value of the channel between the mobile station and the primary base station, and the mobile station and The channel estimate of the channel between the cooperating base stations. Then, the mobile station determines, according to the channel estimation value, whether multi-point cooperative transmission is required, and which form of multi-point cooperative transmission is required, and the codebook that the primary base station and the cooperative base station should adopt in the coordinated cooperative transmission mode (precoding) Matrix), code modulation method, etc. (S202).
• precoding precoding
• Matrix code modulation method
• a request for multi-point cooperative transmission of the request including the above information is transmitted to the primary base station (S203).
• the primary base station determines whether the request can be accepted, and transmits an acknowledgement message to the mobile station (S204), and simultaneously transmits the cooperation information to the cooperative base station (S205), and then transmits data to the mobile station (S206).
• the cooperative base station determines the code modulation mode, the codebook to be used, and the like according to the received cooperation information, and transmits the cooperation data (S207). Thereafter, the mobile station decodes data from the primary base station and from the cooperative base station (S208).
• the primary base station can reasonably schedule the request information according to resources currently being used by the base station and the cooperative base station, for example, if the primary base station finds that the precoding matrix corresponding to each base station indicated in the request information is not used in each base station, The primary base station may receive the request and determine a corresponding multi-point cooperative transmission mode. If the primary base station finds that the base station corresponding precoding matrix indicated in the request information is being used by one of the base stations or each base station, the primary base station may reject The request.
• the transmitted data should be precoded on each subcarrier in the frequency domain of the OFDM system by a preselected codebook, and in each subframe, each subcarrier
• the carriers are numbered by Z , where k is the number of the subcarrier in each OFDM symbol, and 1 is the number of each OFDM symbol.
• the precoded signal is transmitted on M transmit antennas and received by N receive antennas, and the received signal can be expressed as
• r(k, /) ⁇ 0 (k, l)-U 0 - s 0 (k, /) + ⁇ ⁇ (k, l)-U s l (k, /) + ⁇ k, /) ( 0 ⁇ )
• r(kj , ⁇ , , /), UW) and (W) represent the received signal, the channel response matrix, the coding vector, the transmitted signal, and the AWGN noise vector, respectively, and the respective vector dimensions are Wxl, NxM , xl, 1x1 and Wxl.
• the base station as defined herein should be interpreted broadly and should include various means of forming its own service area, serving the communication devices in the service area.
• the steps of the method or algorithm described in connection with the embodiments disclosed herein may be implemented in software executed by hardware (logical means such as a computer).
• the hardware such as a logic device such as a computer
• the hardware may implement the above method or its constituent steps, or cause the hardware (a logical device such as a computer) to function as the device component of the present invention described above. .
• RAM random access memory
• ROM read only memory
• electrically programmable ROM electrically erasable programmable ROM
• registers hard disk, removable disk, CD-ROM, or the art. Any other form of storage medium.

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• 2009
  • 2009-04-30 CN CN2009101369830A patent/CN101877609B/zh not_active Expired - Fee Related
• 2010
  • 2010-04-13 WO PCT/CN2010/071728 patent/WO2010124554A1/zh active Application Filing
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